Radio-Iodide Treatment: From Molecular Aspects to the Clinical View

Navigating the landscape of theranostics in nuclear medicine: current practice and future prospects

Theranostics refers to the combination of diagnostic biomarkers with therapeutic agents that share a specific target expressed by diseased cells and tissues. Nuclear medicine is an exciting component explored for its applicability in theranostic concepts in clinical and research investigations. Nuclear theranostics is based on the employment of radioactive compounds delivering ionizing radiation to diagnose and manage certain diseases employing binding with specifically expressed targets. In the realm of personalized medicine, nuclear theranostics stands as a beacon of potential, potentially revolutionizing disease management. Studies exploring the theranostic profile of radioactive compounds have been presented in this review along with a detailed explanation of radioactive compounds and their theranostic applicability in several diseases. It furnishes insights into their applicability across diverse diseases, elucidating the intricate interplay between these compounds and disease pathologies. Light is shed on the important milestones of nuclear theranostics beginning with radioiodine therapy in thyroid carcinomas, MIBG labelled with iodine in neuroblastoma, and several others. Our perspectives have been put forth regarding the most important theranostic agents along with emerging trends and prospects.

Overexpression of human DNA polymerase theta is a biomarker of aggressive and DNA repair-deficient papillary thyroid cancers

BACKGROUND

DNA polymerase theta (POLQ) is an enzyme that repairs double-strand DNA breaks. POLQ is overexpressed in several cancer types, and increased expression is associated with a poor prognosis. Ablating POLQ function in vitro increases drug sensitivity to agents that cause double-strand DNA breaks, including chemotherapies and ionizing radiation. POLQ's role in thyroid cancer remains poorly understood.

METHODS

Expression of POLQ and other genes of interest were analyzed in 513 papillary thyroid cancers (505 primary tumors and 8 metastatic lesions) and 59 normal thyroid samples available in the Cancer Genome Atlas. The Cancer Genome Atlas RNA and DNA sequencing data were queried with the Xena platform. The Recombination Proficiency Score was calculated to assess DNA repair efficiency. Other signaling events associated with thyroid tumorigenesis and clinical outcomes were analyzed. Univariate and multivariate analyses were performed. Treatment with the POLQ inhibitors ART558 and Novobiocin tested the effect of POLQ inhibition on in vitro thyroid cancer growth.

RESULTS

POLQ expression was increased in papillary thyroid cancers compared to normal thyroid tissue (P < .05). POLQ expression levels were inversely correlated with Recombination Proficiency Score levels (P < .05). POLQ expression was highest in tall cell papillary thyroid cancers and in metastases. Higher POLQ expression was also associated with dedifferentiation, BRAF signaling, and shorter progression-free intervals (P < .05). Treatment with POLQ inhibitors decreased in vitro thyroid cancer growth (P < .05).

CONCLUSION

These findings suggest that increased POLQ expression could serve as a valuable clinical marker and a potential therapeutic target in the treatment of thyroid cancer.

Germline polymorphisms of the NOD2 pathway may predict the effectiveness of radioiodine in differentiated thyroid cancer treatment

PURPOSE

Differentiated thyroid cancer (DTC) presents a complex clinical challenge, especially in patients with distant metastases and resistance to standard treatments. This study aimed to investigate the influence of specific genes and their germline single nucleotide polymorphisms (SNPs) linked to both inflammatory processes and other neoplasms on the clinical and pathological characteristics of DTC, particularly their potential impact on radioiodine (RAI) treatment efficacy.

METHODS

This retrospective analysis involved a cohort of 646 patients diagnosed with DTC after thyroidectomy. Study covering 1998-2014, updated in 2023, included 567 women and 79 men (median age: 49; range: 7-83). SNP selection targeted functional significance, while mutational status was assessed by pyrosequencing for comprehensive characterization. Patient genetic profiles were assessed for associations with disease characteristics, RAI response, and cancer pathology.

RESULTS

Significant correlations emerged between certain SNPs and DTC features. Notably, the NOD2 c.802 T > C variant (rs2066842) was identified as a marker distinguishing between papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC). Moreover, the c.802 T allele was associated with an enhanced response to RAI treatment, indicating a more substantial decrease in posttreatment stimulated thyroglobulin (sTg) concentrations. The NFKB1A allele c.126A (rs696) exhibited connections with lower FTC stages and a reduced probability of multifocality.

CONCLUSION

This study explored the molecular mechanisms of particular SNPs, highlighting the role of NOD2 in innate immunity and the stress response, and its potential impact on RAI efficacy. This research underscores the clinical promise of SNP analysis and contributes to personalized treatment strategies for DTC, emphasizing the relevance of genetic factors in cancer progression and treatment outcomes.

Radioactive iodine refractoriness in Middle Eastern differentiated thyroid cancer: clinical outcome and risk factor analysis

Background

Radioactive iodine refractory differentiated thyroid cancer (RAIR-DTC) has received increasing attention due to its poor prognosis. However, outcomes may vary among patients with RAIR-DTC. The role of clinico-pathological and molecular prognostic factors in survival remains controversial, resulting in difficulty in selecting patients for new targeted therapies. We assessed mortality rate and DTC-specific survival in Middle Eastern RAIR-DTC to identify prognostic factors associated with survival.

Methods

This single center, retrospective study enrolled 268 patients with RAIR-DTC. Mortality rate and DTC-specific survival were analyzed to identify prognostic factors related to survival. Univariate and multivariate analysis were performed using Cox proportional hazards model.

Results

Of the 268 cases of RAIR-DTC, 40.3% (108/268) had absent 131I uptake (either on diagnostic or post-therapy whole body scan), 15.3% (41/268) had progressive disease (PD) despite 131I, 7.5% (20/268) had persistent disease despite cumulative activity of I131 of >600 mCi and 36.9% (n=99/268) developed distant metastasis. On multivariate analysis, age (more than 45 years), presence of metastatic disease and tumors harboring telomerase reverse transcriptase (TERT) promoter mutations were independent prognostic factors for poor DTC-specific survival. Subjects were divided into 3 groups according to the number of risk factors; low risk (no risk factors); intermediate (≤ 2 risk factors); and high risk (all the 3 risk factors). Ten-year DTC-specific survival rates in low, intermediate and high-risk groups were 100.0%, 92.9% and 53.6%, respectively.

Conclusions

The contribution of age greater than 45 years to RAIR-DTC mortality is impactful. Older age, presence of distant metastasis and TERT mutations could be used as early predictors of RAIR-DTC cases. The identification of prognostic factors for poor survival in RAIR-DTC may improve the selection of patients for more personalized surveillance and therapeutic modalities.

Genomic alterations in thyroid cancer: biological and clinical insights

Tumours can arise from thyroid follicular cells if they acquire driver mutations that constitutively activate the MAPK signalling pathway. In addition, a limited set of additional mutations in key genes drive tumour progression towards more aggressive and less differentiated disease. Unprecedented insights into thyroid tumour biology have come from the breadth of thyroid tumour sequencing data from patients and the wide range of mutation-specific mechanisms identified in experimental models, in combination with the genomic simplicity of thyroid cancers. This knowledge is gradually being translated into refined strategies to stratify, manage and treat patients with thyroid cancer. This Review summarizes the biological underpinnings of the genetic alterations involved in thyroid cancer initiation and progression. We also provide a rationale for and discuss specific examples of how to implement genomic information to inform both recommended and investigational approaches to improve thyroid cancer prognosis, redifferentiation strategies and targeted therapies.

The influence of thionamides on intra-thyroidal uptake of 131I during radioiodine-131 treatment of Graves' disease

Graves' disease is one of the most common causes of hyperthyroidism. Guideline recommendations advocate the intake of thionamides for at least 1 year. If hyperthyroidism persists, subsequent radioiodine-131 treatment (RIT) is a therapeutic option. Thionamides are known to influence intra-thyroidal bio-kinetics of iodine and should therefore be discontinued at least 3 days prior to RIT if possible. However, the required therapeutic activity has to be calculated individually by pre-therapeutic measurement of the uptake prior to RIT [radioiodine-131 uptake test (RIUT)] in Germany according to national guidelines. Therefore, the aim of this study was to quantify the influence of thionamides on intra-therapeutic uptake. A cohort of 829 patients with Graves' disease undergoing RIUT and RIT was analysed. Patients were subdivided into three groups. Group A: patients with carbimazole medication (n = 312), group B: patients with methimazole medication (n = 252) and group C: patients without thionamides (n = 265). Group A and B were further subdivided depending on the reduction of dosage of thionamides. In order to analyse the influence of thionamides, the variance of the determined individual extrapolated maximum intra-thyroidal uptake (EMU) between RIUT and RIT within the single groups and within the subgroups was statistically evaluated. When administering an equal dose of thionamides or no thionamides in RIUT and RIT (groups A1, B1 and C) no significant differences were detected when comparing EMU in RIT to EMU in RIUT (p > 0.05). In the subgroups A2-A4 (reduced dosage of carbimazole prior to RIT) EMU was significantly increased in RIT compared to RIUT [21% for a reduction of 0 to < 10 mg/d (A2), 39% for a reduction of 10-15 mg/d (A3) and 80% for a reduction of > 15 mg/d (A4)]. In the subgroups B2-B4 (reduced dosage of methimazole prior to RIT) EMU was as well significantly increased in RIT compared to RIUT [26% for a reduction of 0 to < 10 mg/d (B2), 36% for a reduction of 10-15 mg/d (B3) and 59% for a reduction of > 15 mg/d (B4)]. A significant dose-dependent increase of EMU in RIT compared to EMU in RIUT in patients discontinuing or reducing thionamides was detected. Therefore, thionamides should be discontinued at least 2 days prior to RIUT in order to achieve the designated target dose more precisely and to minimize radiation exposure of organs at risk.

Curcumin induces mitophagy by promoting mitochondrial succinate dehydrogenase activity and sensitizes human papillary thyroid carcinoma BCPAP cells to radioiodine treatment

Thyroid cancer is one of the most common endocrine malignancies. Differentiated thyroid cancer (DTC) treatment is based on the ability of thyroid follicular cells to accumulate radioactive iodide (RAI). DTC generally has a good prognosis. However, tumor dedifferentiation or defect in certain cell death mechanism occurs in a subset of DTC patients, leading to RAI resistance. Therefore, developing novel therapeutic approaches that enhance RAI sensitivity are still warranted. We found that curcumin, an active ingredient in turmeric with anti-cancer properties, rapidly accumulated in the mitochondria of thyroid cancer cells but not normal epithelial cells. Curcumin treatment triggered mitochondrial membrane depolarization, engulfment of mitochondria within autophagosomes and a robust decrease in mitochondrial mass and proteins, indicating that curcumin selectively induced mitophagy in thyroid cancer cells. In addition, curcumin-induced mitophagic cell death and its synergistic cytotoxic effect with radioiodine could be attenuated by autophagy inhibitor, 3-methyladenine (3-MA). Interestingly, the mechanism of mitophagy-inducing potential of curcumin was its unique mitochondria-targeting property, which induced a burst of SDH activity and excessive ROS production. Our data suggest that curcumin induces mitochondrial dysfunction and triggers lethal mitophagy, which synergizes with radioiodine to kill thyroid cancer cells.

Exploring the clinical utility of angioinvasion markers in papillary thyroid cancer: a literature review

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer, and angioinvasion, the invasion of blood vessels by cancer cells, is a crucial pathological feature associated with disease progression and poor prognosis. Thus, a comprehensive search of scientific databases was conducted to identify relevant studies investigating angioinvasion markers in PTC. The selected studies were reviewed and analyzed to assess the clinical significance and potential utility of these markers in predicting angioinvasion and guiding treatment decisions. Numerous studies have investigated various markers associated with angioinvasion in PTC, including oxidative stress, vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), and other angiogenic factors. The results indicate that increased expression of these markers is correlated with the presence and extent of angioinvasion in PTC. Moreover, some studies suggest that these markers can serve as prognostic indicators and guide therapeutic strategies, such as selecting patients for more aggressive treatment approaches or targeted therapies. The findings from the reviewed literature highlight the potential clinical utility of angioinvasion markers in PTC. The identification and validation of reliable markers can aid in assessing the risk of angioinvasion, predicting disease progression, and optimizing treatment decisions for patients with PTC. However, further research and validation on larger patient cohorts are necessary to establish the robustness and generalizability of these markers in clinical practice.

The role of miR-139-5p in radioiodine-resistant thyroid cancer

PURPOSE

Radioiodine I-131 (RAI) is the therapy of choice for differentiated thyroid cancer (DTC). Between 5% and 15% of DTC patients become RAI refractory, due to the loss of expression/function of iodide metabolism components, especially the Na/I symporter (NIS). We searched for a miRNA profile associated with RAI-refractory DTC to identify novel biomarkers that could be potential targets for redifferentiation therapy.

METHODS

We analyzed the expression of 754 miRNAs in 26 DTC tissues: 12 responsive (R) and 14 non-responsive (NR) to RAI therapy. We identified 15 dysregulated miRNAs: 14 were upregulated, while only one (miR-139-5p) was downregulated in NR vs. R tumors. We investigated the role of miR-139-5p in iodine uptake metabolism. We overexpressed miR-139-5p in two primary and five immortalized thyroid cancer cell lines, and we analyzed the transcript and protein levels of NIS and its activation through iodine uptake assay and subcellular protein localization.

RESULTS

The finding of higher intracellular iodine levels and increased cell membrane protein localization in miR-139-5p overexpressing cells supports the role of this miRNA in the regulation of NIS function.

CONCLUSIONS

Our study provides evidence of miR-139-5p involvement in iodine uptake metabolism and suggests its possible role as a therapeutic target in restoring iodine uptake in RAI-refractory DTC.

[Therapy concepts for thyroid carcinoma]

Theranostics via the sodium iodide symporter (NIS) offer a unique option in differentiated thyroid carcinoma. The diagnostic and therapeutic nuclides have similar uptake and kinetics, making the NIS the most important theranostic target in this disease. Radioiodine refractory thyroid carcinomas (RRTC) are characterised by reduced/absent NIS expression, thus eliminating this structure as a theranostic target. Also due to limited therapeutic options, there are approaches to generate new theranostic targets in RRTC, via the expression of somatostatin receptors (SSTR) or the prostate-specific membrane antigen (PSMA), but the current evidence does not yet allow a final evaluation of the prospects of success.

Poly (lactic-co-glycolic acid)-encapsulated iodine-131 nanoparticles fabricated with rhTSH induce apoptosis and immobilization of thyroid cancer cells

Background

Aggressive thyroid carcinoma (ATC) usually loses radioiodine avidity to iodine-131 (¹³¹I) due to the downregulation of sodium/iodide symporter (NIS). The expression of thyroid stimulating hormone receptor (TSHR) is more persistent than NIS and the administration of recombinant human thyroid stimulating hormone (rhTSH) promotes de novo NIS synthesis. Hence, exploring methods integrating ¹³¹I with rhTSH might be a feasible therapeutic strategy for selective delivery of ¹³¹I into thyroid cancer to fortify the effect of radioiodine ablation.

Methods

The ¹³¹I, poly (lactic-co-glycolic acid) (PLGA) and rhTSH were used to synthesize of the ¹³¹I-PLGA-rhTSH nanoparticles. The characteristics of the ¹³¹I-PLGA-rhTSH nanoparticles was determined using a light microscopy, scanning electron microscopy (SEM), autoradiography and immunofluorescence (IF) staining. The diameter of the ¹³¹I-PLGA-rhTSH nanoparticles was measured with a Mastersizer 3000, and the encapsulation efficiency (EF) of ¹³¹I in ¹³¹I-PLGA-rhTSH nanoparticles and the radioactivity of a single nanoparticle were determined. Then, the mouse tumor xenograft model was established, and the biodistribution and effect of ¹³¹I-PLGA-rhTSH nanoparticles on apoptosis of thyroid cance cells were investigated in vivo. Thereafter, the role of ¹³¹I-PLGA-rhTSH nanoparticles in cell viability using cell counting kit-8 and lactate dehydrogenase (LDH) release assays. Subsequently, the underlying mechanism of ¹³¹I-PLGA-rhTSH nanoparticles in reducing cell viability was assessed using immunostaining, boyden invasion assays and phalloidin staining.

Results

Our results showed that the method of developing nanoparticles-encapsulated ¹³¹I using poly (lactic-co-glycolic acid) (PLGA) and modified with rhTSH (¹³¹I-PLGA-rhTSH), was a feasible avenue for the integration of ¹³¹I and rhTSH. Meanwhile, the encapsulation efficiency (EF) of ¹³¹I-PLGA-rhTSH nanoparticles was approximately 60%, and the radioactivity of a single nanoparticle was about 1.1×10-2 Bq. Meanwhile, the ¹³¹I-PLGA-rhTSH nanoparticles were selectively delivered into, gradually enriched and slowly downregulated in xenograft tumor after the administration of ¹³¹I-PLGA-rhTSH nanoparticles through tail vein in mouse tumor xenograft model. Thereafter, the tumor weight was significantly reduced after the administration of ¹³¹I-PLGA-rhTSH nanoparticles. Subsequently, the application of ¹³¹I-PLGA-rhTSH nanoparticles facilitated apoptosis and attenuated immobilization via inhibiting F-actin assembling of FTC-133 cells.

Conclusion

The present study develops a suitable approach integrating ¹³¹I and rhTSH, and this strategy is a feasible regimen enhancing the effect of radioiodine ablation for the treatment of thyroid cancer.

Thyroid Carcinoma: A Review for 25 Years of Environmental Risk Factors Studies

Environmental factors are established contributors to thyroid carcinomas. Due to their known ability to cause cancer, exposure to several organic and inorganic chemical toxicants and radiation from nuclear weapons, fallout, or medical radiation poses a threat to global public health. Halogenated substances like organochlorines and pesticides can interfere with thyroid function. Like phthalates and bisphenolates, polychlorinated biphenyls and their metabolites, along with polybrominated diethyl ethers, impact thyroid hormones biosynthesis, transport, binding to target organs, and impair thyroid function. A deeper understanding of environmental exposure is crucial for managing and preventing thyroid cancer. This review aims to investigate the relationship between environmental factors and the development of thyroid cancer.

The influence of thyroid hormone medication on intra-therapeutic half-life of 131I during radioiodine therapy of solitary toxic thyroid nodules

Despite a significantly improved dietary iodine supply, solitary toxic thyroid nodules (STN) are still a common clinical problem in former iodine deficient areas. Radioiodine treatment (RIT) is a well-established therapeutic option with few side effects and high success rates. As radioiodine biokinetics are individual for every patient, the necessary activity has to be calculated individually by a pre-therapeutic measurement of the intra-therapeutic effective half-life (EHL) in a radioiodine uptake test (RIUT). A suppressive medication with triiodothyronine (T3) or tetraiodothyronine (T4) is often needed to suppress uptake in normal thyroid tissue. Therefore, the aim of this study was to quantify the possible influence of this medication on intra-therapeutic radioiodine biokinetics. A cohort of 928 patients with STN undergoing RIUT and RIT was analysed. Patients were subdivided into 3 groups. Group T3: medication with T3 (n = 274), group T4: medication with T4 (n = 184) and group NM: no additional medication (n = 470). The T3 and T4 subgroups were further subdivided depending on the dose of thyroid hormone medication. In order to analyse the influence of thyroid hormone medication on individual intra-thyroidal biokinetics, the variance of the determined individual EHL between RIUT and RIT within the single groups and within the subgroups was investigated. EHL was significantly decreased between RIUT and RIT in the T3 and T4 subgroups (EHL: T3: 5.9 ± 1.1 d in RIUT and 3.3 ± 1.4 d in RIT (− 43%) (p < 0.05); T4: 5.9 ± 1.2 d in RIUT and 3.4 ± 1.5 d in RIT (− 42%) (p < 0.05). The decrease of EHL did not differ statistically between T3 or T4. However, both showed a highly significant difference compared to the NM group (p < < 0.05). A further subgroup analysis showed a significant dependence of the decrease in EHL related to the dose of thyroid hormone medication of 35–58% (T3) and 15–67% (T4) (p < 0.05). A significantly reduced EHL compared to RIUT in patients receiving thyroid hormone medication was detected. Moreover, a significant correlation between the dose of thyroid hormone medication (T3 or T4) and the decrease of EHL was found. Therefore, an adaption of the calculated activity should be considered in RIUT to obtain the required radiation dose in RIT of patients suffering from STN.

Radiotheranostics in oncology: current challenges and emerging opportunities

Structural imaging remains an essential component of diagnosis, staging and response assessment in patients with cancer; however, as clinicians increasingly seek to noninvasively investigate tumour phenotypes and evaluate functional and molecular responses to therapy, theranostics - the combination of diagnostic imaging with targeted therapy - is becoming more widely implemented. The field of radiotheranostics, which is the focus of this Review, combines molecular imaging (primarily PET and SPECT) with targeted radionuclide therapy, which involves the use of small molecules, peptides and/or antibodies as carriers for therapeutic radionuclides, typically those emitting α-, β- or auger-radiation. The exponential, global expansion of radiotheranostics in oncology stems from its potential to target and eliminate tumour cells with minimal adverse effects, owing to a mechanism of action that differs distinctly from that of most other systemic therapies. Currently, an enormous opportunity exists to expand the number of patients who can benefit from this technology, to address the urgent needs of many thousands of patients across the world. In this Review, we describe the clinical experience with established radiotheranostics as well as novel areas of research and various barriers to progress.

Advances in Thyroid Carcinoma

"Thyroid cancer" encompasses a heterogeneous group of tumors that range from the predominant papillary thyroid cancer (PTC) subtype, which shows excellent survival rates, to the poorly differentiated (PDTC) and anaplastic thyroid cancer (ATC) forms, accounting for most of the disease-related morbidity and mortality [...].

[Therapy concepts for thyroid carcinoma]

Theranostics via the sodium iodide symporter (NIS) offer a unique option in differentiated thyroid carcinoma. The diagnostic and therapeutic nuclides have similar uptake and kinetics, making the NIS the most important theranostic target in this disease. Radioiodine refractory thyroid carcinomas (RRTC) are characterised by reduced/absent NIS expression, thus eliminating this structure as a theranostic target. Also due to limited therapeutic options, there are approaches to generate new theranostic targets in RRTC, via the expression of somatostatin receptors (SSTR) or the prostate-specific membrane antigen (PSMA), but the current evidence does not yet allow a final evaluation of the prospects of success.

Redox Homeostasis in Thyroid Cancer: Implications in Na+/I- Symporter (NIS) Regulation

Radioiodine therapy (RAI) is a standard and effective therapeutic approach for differentiated thyroid cancers (DTCs) based on the unique capacity for iodide uptake and accumulation of the thyroid gland through the Na⁺/I⁻ symporter (NIS). However, around 5–15% of DTC patients may become refractory to radioiodine, which is associated with a worse prognosis. The loss of RAI avidity due to thyroid cancers is attributed to cell dedifferentiation, resulting in NIS repression by transcriptional and post-transcriptional mechanisms. Targeting the signaling pathways potentially involved in this process to induce de novo iodide uptake in refractory tumors is the rationale of “redifferentiation strategies”. Oxidative stress (OS) results from the imbalance between ROS production and depuration that favors a pro-oxidative environment, resulting from increased ROS production, decreased antioxidant defenses, or both. NIS expression and function are regulated by the cellular redox state in cancer and non-cancer contexts. In addition, OS has been implicated in thyroid tumorigenesis and thyroid cancer cell dedifferentiation. Here, we review the main aspects of redox homeostasis in thyrocytes and discuss potential ROS-dependent mechanisms involved in NIS repression in thyroid cancer.

Mesenchymal Stem Cells Delivery in Individuals with Different Pathologies: Multimodal Tracking, Safety and Future Applications

Due to their ease of isolation and their properties, mesenchymal stem cells (MSCs) have been widely investigated. MSCs have been proved capable of migration towards areas of inflammation, including tumors. Therefore, they have been suggested as vectors to carry therapies, specifically to neoplasias. As most of the individuals joining clinical trials that use MSCs for cancer and other pathologies are carefully recruited and do not suffer from other diseases, here we decided to study the safety and application of iv-injected MSCs in animals simultaneously induced with different inflammatory pathologies (diabetes, wound healing and tumors). We studied this by in vitro and in vivo approaches using different gene reporters (GFP, hNIS, and f-Luc) and non-invasive techniques (PET, BLI, or fluorescence). Our results found that MSCs reached different organs depending on the previously induced pathology. Moreover, we evaluated the property of MSCs to target tumors as vectors to deliver adenoviruses, including the interaction between tumor microenvironment and MSCs on their arrival. Mechanisms such as transdifferentiation, MSC fusion with cells, or paracrine processes after MSCs homing were studied, increasing the knowledge and safety of this new therapy for cancer.

Coating an adenovirus with functionalized gold nanoparticles favors uptake, intracellular trafficking and anti-cancer therapeutic efficacy

Adenoviral (Ad) vectors have proven to be important tools for gene and cell therapy, although some issues still need to be addressed, such as undesired interactions with blood components and off-target sequestration that ultimately hamper efficacy. In the past years, several organic and inorganic materials have been developed to reduce immunogenicity and improve biodistribution of Ad vectors. Here we investigated the influence of the functionalization of 14 nm PEGylated gold nanoparticles (AuNPs) with quaternary ammonium groups and an arginine-glycine-aspartic acid (RGD)-motif on the uptake and biodistribution of Ad vectors. We report the formation of Ad@AuNPs complexes that promote cell attachment and uptake, independently of the presence of the coxsackievirus and adenovirus receptor (CAR) and α_vβ₃ and α_vβ₅ integrins, significantly improving transduction without limiting Ad bioactivity. Besides, the presence of the RGD peptide favors tumor targeting and decreases Ad sequestration in the liver. Additionally, tumor delivery of a coated Ad vector expressing the human sodium iodide symporter (hNIS) by mesenchymal stem cells induces increased accumulation of radioactive iodine (¹³¹I) and tumor volume reduction compared to naked Ad-hNIS, highlighting the promising potential of our coating formulation in cancer gene therapy. STATEMENT OF SIGNIFICANCE: Modification of adenoviral vectors with lipids and polymers can reduce interactions with blood components and increase tumor accumulation; however, increased toxicity and reduced transduction efficiency were indicated. Coating with gold nanoparticles has proven to be a successful strategy for increasing the efficiency of transduction of receptor-defective cell lines. Here we explore the contribution of cell surface receptors on the mechanisms of entry of Ad vectors coated with gold nanoparticles in cell lines with varying degrees of resistance to infection. The enhancement of the anti-tumoral effect shown in this work provides new evidence for the potential of our formulation.

Curcumin induces autophagic cell death in human thyroid cancer cells

Curcumin, a polyphenolic compound, is a well-known anticancer agent, although its poor bioavailability remains a big concern. Recent studies suggest that autophagy-targeted therapy may be a useful adjunct treatment for patients with thyroid cancer. Curcumin acts as an autophagy inducer on many cancer cells. However, little is known about the exact role of curcumin on thyroid cancer cells. In the present study, curcumin significantly inhibited the growth of thyroid cancer cells. Autophagy was markedly induced by curcumin treatment as evidenced by an increase in LC3-II conversion, beclin-1 accumulation, p62 degradation as well as the increased formation of acidic vesicular organelles (AVOs). 3-MA, an autophagy inhibitor, partially rescued thyroid cancer cells from curcumin-induced cell death. Additionally, curcumin was found to exert selective cytotoxicity on thyroid cancer cells but not normal epithelial cells and acted as an autophagy inducer through activation of MAPK while inhibition of mTOR pathways. Hyperactivation of the AKT/mTOR axis was observed in the majority of PTC samples we tested, and thyroid cancer cell lines along with cancer tissue specimens sustained a low basal autophagic activity. Taken together, our results provide new evidence that inducing autophagic cell death may serve as a potential anti-cancer strategy to handle thyroid cancer.

KMT2B promotes SHPRH expression to regulate 131I sensitivity in thyroid carcinoma cells by affecting FYN protein stability

Radioiodine (¹³¹I) is one of the most well-known and widely used targeted therapies. In thyroid carcinoma (THCA), it has been applied for more than eight decades and is still being utilized to eliminate remnants after resection and to reduce tumor metastases. Here, we aimed to investigate if lysine methyltransferase 2B (KMT2B) silencing could confer ¹³¹I resistance to THCA cells and the epigenetic mechanism behind. RT-qPCR, immunohistochemistry and western blot revealed that KMT2B was poorly expressed in THCA cells, and ¹³¹I resistance of cells led to a further decrease in KMT2B expression. EdU, colony formation, TUNEL, and tumor growth and metastasis assays showed that overexpression of KMT2B sensitized THCA cell to ¹³¹I and inhibited cell growth and metastasis. Further bioinformatics prediction and functional assay validation revealed that KMT2B elevated SHPRH expression via H3K4me3 modification in the SHPRH promoter, and that SHPRH modulated FYN ubiquitination, thereby promoting its protein degradation. We finally proved that the ¹³¹I-resistant cells regained resistance to ¹³¹I by FYN overexpression in the presence of KMT2B overexpression in vitro and in vivo. Therefore, we conclude that the overexpression of KMT2B represents a potential target for THCA therapy.

The PDZ protein SCRIB regulates sodium/iodide symporter (NIS) expression at the basolateral plasma membrane

The sodium/iodide symporter (NIS) expresses at the basolateral plasma membrane of the thyroid follicular cell and mediates iodide accumulation required for normal thyroid hormonogenesis. Loss-of-function NIS variants cause congenital hypothyroidism due to impaired iodide accumulation in thyroid follicular cells underscoring the significance of NIS for thyroid physiology. Here we report novel findings derived from the thorough characterization of the nonsense NIS mutant p.R636* NIS-leading to a truncated protein missing the last eight amino acids-identified in twins with congenital hypothyroidism. R636* NIS is severely mislocalized into intracellular vesicular compartments due to the lack of a conserved carboxy-terminal type 1 PDZ-binding motif. As a result, R636* NIS is barely targeted to the plasma membrane and therefore iodide transport is reduced. Deletion of the PDZ-binding motif causes NIS accumulation into late endosomes and lysosomes. Using PDZ domain arrays, we revealed that the PDZ-domain containing protein SCRIB binds to the carboxy-terminus of NIS by a PDZ-PDZ interaction. Furthermore, in CRISPR/Cas9-based SCRIB deficient cells, NIS expression at the basolateral plasma membrane is compromised, leading to NIS localization into intracellular vesicular compartments. We conclude that the PDZ-binding motif is a plasma membrane retention signal that participates in the polarized expression of NIS by selectively interacting with the PDZ-domain containing protein SCRIB, thus retaining the transporter at the basolateral plasma membrane. Our data provide insights into the molecular mechanisms that regulate NIS expression at the plasma membrane, a topic of great interest in the thyroid cancer field considering the relevance of NIS-mediated radioactive iodide therapy for differentiated thyroid carcinoma.

Next-Generation Molecular Imaging of Thyroid Cancer

An essential aspect of thyroid cancer (TC) management is personalized and precision medicine. Functional imaging of TC with radioiodine and [18F]FDG has been frequently used in disease evaluation for several decades now. Recently, advances in molecular imaging have led to the development of novel tracers based on aptamer, peptide, antibody, nanobody, antibody fragment, and nanoparticle platforms. The emerging targets-including HER2, CD54, SHP2, CD33, and more-are promising targets for clinical translation soon. The significance of these tracers may be realized by outlining the way they support the management of TC. The provided examples focus on where preclinical investigations can be translated. Furthermore, advances in the molecular imaging of TC may inspire the development of novel therapeutic or theranostic tracers. In this review, we summarize TC-targeting probes which include transporter-based and immuno-based imaging moieties. We summarize the most recent evidence in this field and outline how these emerging strategies may potentially optimize clinical practice.